What does handle mean? Is it c, csdn how to look up about the handle

A handle is a (usually 32-bit) integer that represents an object. Handles in Windows are similar to file handles used in traditional C or MS-DOS programming. Programs almost always get a handle by calling a Windows function.

The program uses this handle in other Windows functions to use the object it represents.

In Windows, there can be many types of windows. A window can be a rectangular enclosed area on the screen, such as a familiar application window. Controls on a form, such as a list box or scroll bar, can also be windows, but not all types of controls are windows.

The icons on the desktop and the desktop itself are also windows. Because all of these types of objects are windows, Windows can handle them in a similar way. Windows gives each window a unique handle through which it can be manipulated.

Many API functions can return a handle or accept a handle as an argument.

When a window is created, Windows assigns it a handle, and the handle is released when the window disappears.

In the Windows environment, handles are used to identify items, which include:

module

Task

instance

file

Block of memory

menu

Control

Font

Resources, including icons, cursors, strings, etc.

GDI objects, including bitmaps, brushes, metafiles, palettes, pens, regions, and device contexts.

Instead of using a physical address to identify a block of memory, a file, a task, or a dynamically loaded module, the Windows API assigns a definite handle to these items and returns the handle to the application, which is then manipulated through the handle.

From the above 2 definitions, we can see that a handle is an identifier, which is used to identify an object or project, it is like our name, everyone will have one, different people's names are different, but there may also be a person whose name is the same as yours. In terms of data type, it's just a 16-bit unsigned integer. Applications almost always get a handle by calling a Windows function, which can then be used by other Windows functions to reference the corresponding object.

In Windows programming, a large number of handles are used, such as: hinstance (instance handle), hbitmap (bitmap handle), hdc (device description table handle), hicon (icon handle).